Patent GB-120205-A (GB)
Title: Process for Evaporating Liquids.
Inventor: MORTERUD EINAR
IPC: B01D5/00
Filed: 1918-10-01
Abstract: 120,205. Morterud, E. Oct. 26, 1917, [Convention date]. Vapours, utilizing jor effecting further evaporation; film evaporators; spray evaporators; evaporating by contact with hot liquid.-In evaporating liquid by means of the heat of the vapours generated in the evaporation after they have been compressed, the heating of the liquid is effected without bringing it into contact with a heat-exchanging apparatus, by the use of a heat-transmitting medium which is heated by direct contact with the compressed vapours. This heattransmitting medium may be used to heat the liquid (1) by direct contact, (2) by radiation, and (3) by means of another heat-transmitting medium, termed a heat-conveyer, which is heated by the neat-transmitting medium and is afterwards brought into contact with the liquid. (1) When the liquid is heated by direct contact, a liquid heat-transmitting medium is used. The heat-transmitting medium is heated by direct contact with the compressed vapours, as by passing it in the form of spray through a compression chamber B, Fig. 1, which receives the vapours coming from the compressor C. The heated medium separates from the condensate at the base of the compression chamber Band. flows through a pipe g to the evaporator A. When the medium is heavier than the liquid to be evaporated, it is sprayed into the liquid, and, collecting at the base of the evaporator, flows through a trap E to a pump F which forces it to the top of the compression chamber B. The vapours formed are collected by a pipe a and led to the compressor C. The liquid is preheated in an exchanger D by means of condensate from the vessel B. When the medium is lighter than the liquid to be evaporated, both liquids may be sprayed into the evaporator, a pump being provided to circulate the liquid from the base of the evaporator to the spraying-device. (2) In order to heat the liquid by radiation, the evaporator is fitted with surfaces x, y, Fig. 3, over which the medium and the liquid respectively flow in streams. The liquid and the medium are collected separately, the liquid being circulated by a pump P. This arrangement is particularly applicable when a light medium such as oil is used. (3) When a heat-conveyer is used, the heat of the compressed vapours is first absorbed by means cf a liquid or solid heat-transmitting medium, and the vapour of the liquid to be evaporated is used as a heat-conveyer. When the heat-transmitting medium is a liquid, the evaporator used resembles that shown in Fig. 3, the surfaces x, y being however arranged edge to edge instead of face to face. A fan is provided to circulate the steam or other heat-conveyer through the evaporator so that the steam is superheated while passing over the surfaces x in contact with liquid from the compression chamber, and afterwards gives up its superheat to the liquid flowing over the surfaces y. When a solid is used to absorb heat from the compressed vapours, duplicate chambers, each consisting of a closed circuit comprising evaporating surfaces and heat-accumulators containing the' solid, are used alternately as compression chambers and evaporators, the heat stored at the compression stage being transmitted to the circulating steam at the eyapcration stage.